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A Phosphorus Bisylide: Exploring a New Class of Superbases with Two Interacting Carbon Atoms as Basicity Centers
Author(s) -
Kögel Julius F.,
Margetić Davor,
Xie Xiulan,
Finger Lars H.,
Sundermeyer Jörg
Publication year - 2017
Publication title -
angewandte chemie international edition
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.831
H-Index - 550
eISSN - 1521-3773
pISSN - 1433-7851
DOI - 10.1002/anie.201612446
Subject(s) - superbase , protonation , chemistry , proton , naphthalene , carbon fibers , crystallography , proton affinity , phosphorus , computational chemistry , ion , organic chemistry , materials science , physics , quantum mechanics , composite number , composite material , catalysis
Herein we present the first superbase MHPN with two interacting P‐ylide entities. Unlike classical proton sponges, this novel compound class has carbon atoms as basicity centers which are forced into close proximity by a naphthalene scaffold. The bisylide exhibits an experimental p K BH + value of 33.3±0.2 on the MeCN scale and a calculated gas‐phase proton affinity of 277.9 kcal mol −1 (M062X/6‐311+G**//M062X/6‐31G*+ZPVE method) exceeding that of the corresponding monoylide by nearly 15 kcal mol −1 . The origin of the unexpectedly high basicity of the new bisylide was investigated by NMR spectroscopic methods, single‐crystal X‐ray diffraction as well as theoretical calculations and can be partly attributed to the rapid exchange of the “acidic” proton between the two basic carbon atoms after protonation.